User:Tiakortman/sandbox
Discoveries of Helium Stars
[edit]In 2011, GALEX J184559.8−413827 (also known as J1845−4138) was labeled a "hot subdwarf." This means that GALEX J184559.8-413827 is characterized with being hotter and larger than the sun, while also being completely devoid of hydrogen. From these classifications, this hot subdwarf is considered to be a extreme helium star. In South Africa, the Southern Africa Large Telescope (SALT) has been monitoring this massive helium star's high-resolution spectrum.[1]
A Hypervelocity star (HVSs) called US 708, HVS 2 has been labeled a helium star. Being the most fast rotator, it is thought to be a remnant of a thermonuclear supernova.[2]
The helium star's great capability of transforming into other stellar objects has been observed over the years. In 2014, a helium nova named V445 Puppis exploded, along with a following explosion of the star SN2012Z, causing a high-mass transfer between the two. It is observed to have caused a growing helium star that has the potential to transform into a red giant after losing it's hydrogen envelope in the future.[3]
Origin of Helium Stars
[edit]After a binary mass transfer, a helium star is formed. This may only happen if these 2 binary masses share the same type of envelope phase.[4]
Merging
[edit]Often when a supernova dies, long gamma ray bursts are emitted. In 2010 it was observed that the aftermath of a supernova death caused a helium star to merge with a neuron star. This led to the merger going through a common envelope phase (losing it's hydrogen) and emitting gamma ray bursts.[5]
 | This is a user sandbox of Tiakortman. You can use it for testing or practicing edits. This is not the sandbox where you should draft your assigned article for a dashboard.wikiedu.org course. To find the right sandbox for your assignment, visit your Dashboard course page and follow the Sandbox Draft link for your assigned article in the My Articles section. |
- ^ "Rare extreme helium star identified by astronomers". Retrieved 2018-03-18.
- ^ Geier, S.; Fürst, F.; Ziegerer, E.; Kupfer, T.; Heber, U.; Irrgang, A.; Wang, B.; Liu, Z.; Han, Z. (2015-03-06). "The fastest unbound star in our Galaxy ejected by a thermonuclear supernova". Science. 347 (6226): 1126–1128. doi:10.1126/science.1259063. ISSN 0036-8075. PMID 25745168.
- ^ "Science in Context - Document". link.galegroup.com. Retrieved 2018-03-18.
- ^ "Science in Context - Document". link.galegroup.com. Retrieved 2018-03-25.
- ^ Thone, C.C.; Postigo, A. de Ugarte; Fryer, C.L.; Page, K.L.; Gorosabe, J.; Aloy, M.A.; Perley, D.A.; Kouveliotou, C.; Janka, H.T. (2011-12-01). "The unusual [gamma]-ray burst GRB101225A from a helium star/neutron star merger at redshift 0.33". Nature. 480 (7375). doi:10.1038/naturel0611.